Gripping system for automated guided vehicles

Abstract

This invention discloses a clamping system for automated guided vehicles (AGVs) and such AGVs. The clamping system for automatically clamping and pulling / pushing trolleys includes a unique clamping end actuator that ensures controlled steering of the trolley while allowing the trolley to roll relative to the AGV body. The end actuator includes means for indicating the connection status between the trolley and the clamping system, thereby ensuring reliable, safe, and efficient trolley clamping and pulling operations.

Description

Technical Field

[0001] This invention relates to a clamping system for automated guided vehicles (AGVs), which is used for docking and disengaging trolleys and for pulling and pushing trolleys. More specifically, this invention relates to a manipulator-type clamping system. Background Technology

[0002] The movement of goods within or between structures has already created problems to some extent. For example, hospitals with more than 500 beds spend a considerable amount of time physically moving fabrics, medical specimens, medicines, blood products, patient charts, X-ray equipment, and meals.

[0003] Today, many transportation options exist as commercial products, such as conveyor belts, pneumatic tubes, omnidirectional trolleys, and mobile robots. Mobile robots, especially automated guided vehicles (AGVs), are equipped with computer-controlled drive systems, which allow for automated guidance between multiple locations.

[0004] It is well known in the art to use a rear-mounted traction device on an AGV to tow a trolley. Typically, a commercially available hook-up device and ball joint are mounted at one end of the AGV, usually at the rear, where a trolley including a releasable socket and a tow bar is attached.

[0005] U.S. Patent Application No. 15 / 566516 (Publication No. US2018 / 0281178) discloses a mobile robot system comprising an AGV and a gripping device mounted on the AGV. The AGV includes wheel drive motors, an onboard computer, means for navigating, orienting, and maneuvering in a moving environment with obstacles, a sensor system, and a wireless communication system for receiving and transmitting signals. The gripping system includes a base for attaching the gripping system to the AGV, an arm, and a gripper for gripping a cart. A major challenge with such gripping systems is that the position of the AGV relative to the cart must be very precise in order to grip it. This may require multiple docking and re-docking attempts, and / or docking at low speeds. Another challenge with the prior art is the lack of safety indication regarding whether the gripper is correctly aligned with the connection parts of the cart before and / or while the gripping mechanism is activated. This can lead to an incorrect / weak connection between the clamping device and the trolley, potentially requiring additional connection attempts, increasing wear and tear on the connection mechanism, and causing the trolley to be lost during transport.

[0006] Another challenge with existing solutions is the lack of safety instructions regarding whether the trolley is properly detached from the vehicle. This can lead to situations where the trolley remains inadvertently attached to the vehicle while it is in "trolley-free" driving mode, and the additional footprint of the inadvertently attached trolley is not taken into account when navigating around obstacles and structural elements.

[0007] The object of this invention is to improve upon existing technology and provide a vehicle clamping system for AGVs with a safe, reliable, and fast clamping mechanism, as well as an AGV having such a system. Another object of this invention is to increase the possibility of smoothly clamping various trolleys for safe pulling or pushing operations, these trolleys may or may not be specifically designed for automated transport. Yet another object is to provide safer operation of AGVs with clamping systems when no trolleys should be connected. Summary of the Invention

[0008] According to one aspect of the invention, a clamping system 1 for an automated guided vehicle (AGV) is disclosed. The clamping system 1 includes a base 2 for attaching the clamping system 1 to a body 4 of the AGV, and an arm 6 for manipulating an end effector 8 for clamping a cart towed or pushed by the AGV. The arm 6 is pivotally attached to the base 2 at one end, thereby allowing deflection movement of the arm 6 relative to the AGV. An end effector 8 is provided at the other end of the arm 6. The height of the end effector 8 is adjusted by an actuator 14 of the arm 6.

[0009] End effector 8 is attached to arm 6 via pivot connector 10. This allows for rolling movement of end effector 8 relative to arm 6, while limiting deflection movement of the end effector relative to the arm. If only one of the sensor arms 20a, 20b is pressed against the connecting part of the trolley,

[0010] Two sensor arms 20a, 20b of the end effector 8 are adapted to pivot the end effector 8 about its pivoting connector 10. The sensor arms 20a, 20b are also adapted to activate sensors 22a, 22b when pressed against the connecting part of the trolley, thereby sending a signal to the control system of the clamping device to indicate whether the end effector is in the correct position for applying clamping force to the connecting part of the trolley. The end effector 8 is provided with a hook 11 and a plurality of supports 13a, 13b, which are adapted to apply clamping force to a portion of the trolley frame by moving the hook 11 in the direction of the supports 13a, 13b. Another sensor activation element 11a is attached to the hook 11 to activate another sensor 23 attached to the front end face 21. When sensor 23 is activated, it sends a signal to the control system of the clamping device indicating that the hook 11 is fully retracted.

[0011] According to another aspect of the present invention, an automated guided vehicle (AGV) including a gripping system 1 is disclosed. The AGV includes drive wheels, a robot body 4 mounted on the drive wheels, a control system utilizing a navigation system, and a gripping system 1 mounted on the robot body 4 for attaching a trolley to the vehicle. The AGV also includes at least one proximity sensor 4.1, 4.2 mounted on the robot body 4. The control system is coupled to the at least one proximity sensor 4.1, 4.2 for adjusting the calculated robot position and detecting any obstacles. Attached Figure Description

[0012] The features of the invention, which are considered novel and inventive, are specifically set forth in the appended claims. However, the invention itself can be best understood by referring to the following detailed description of exemplary embodiments given in a non-limiting example of the invention, taken in conjunction with the accompanying drawings, wherein:

[0013] Figure 1 A clamping system according to the invention, mounted on an AGV, is shown.

[0014] Figure 2 An end effector of the clamping system according to the present invention is shown.

[0015] Figure 3 An end effector of a clamping system according to the invention is shown, which clamps elements of a trolley frame.

[0016] Preferred embodiments of the invention will now be described with reference to the accompanying drawings. Each figure contains the same numbers for the same or equivalent elements. Detailed Implementation

[0017] Numerous specific details are presented to provide a complete and comprehensive description of embodiments of the invention. However, those skilled in the art will understand that the exemplary embodiments are not intended to limit the application of the invention in the absence of these specific instructions. To avoid any misinterpretation, well-known methods, procedures, and components are not described in detail with respect to the embodiments. Furthermore, this description should not limit the invention to the given exemplary embodiments, but is merely considered as one of the possible specific implementations of the invention.

[0018] Figure 1 The clamping system 1 of the AGV is shown. The clamping system 1 includes a base 2, an arm 6, and an end effector 8 with sensors 23, 22a, and 22b.

[0019] The base 2 includes means (e.g., bolt holes) for attaching the base 2 to the AGV, and an electrical interface (not shown) for connecting the clamping system to the AGV so that the AGV can control the clamping system. The base 2 may include portions 5 (e.g., recesses or openings) for interacting with the fixing means 9 of the clamping system arm 6 to fix the arm 6 in a fixed position when a fixed position is required. The base 2 also includes means 7 (e.g., a vertical shaft) for attaching the arm 6 to the base 2. The arm attachment means 7 is configured to receive the arm 6 so that the arm 6 can rotate at least partially about the vertical axis of the attachment point, i.e., deflected relative to the body 4 of the AGV.

[0020] The arm 6 also includes a frame 16. The frame 16 is attached at one end to a means 7 for attaching the arm 6 to the base 2. Opposite ends of the frame 16 have end actuators 8 attached thereto. The frame 16 may include an upper frame element 16a and a lower frame element 16b. The upper frame element 16a and / or the lower frame element 16b are attached at one end to the means 7 for attaching the arm 6 to the base 2, and at opposite ends to a sliding rod 16c. The frame 16 is preferably rigid. The arm 6 also includes an actuator 14 adapted to adjust the angle of the lifting rods 18a, 18b relative to a horizontal plane, thereby adjusting the height of the sliding element 17 and the height of the end actuator 8. The arm actuator 14 is fixed at one end to the lower frame element 16b and at the other end to the lifting rod 18a or a set of lifting rods 18a, 18b. One end of each of the lifting rods 18a and 18b is pivotally attached at attachment point 19c to the first end of each of the support rods 19a and 19b. The second end of each of the support rods 19a and 19b is pivotally attached at attachment point 19d to the lower frame element 16b. The lifting rods 18a and 18b are pivotally attached at their respective second ends to a sliding element 17. When the actuator 14 of the arm 6 acts on the lifting rods 18a and 18b, the sliding element 17 slides up and down along the sliding rod 16c. The sliding element 17 is connected to the end actuator 8 via a pivoting connection 10. The pivoting connection 10 allows the end actuator 8 to partially roll relative to the AGV's base 2 and body 4.

[0021] The arm 6 includes a fixing device 9 for locking the arm 6 relative to the body 4 of the AGV in a laterally stationary and stable position. The locking device 9 can be any electrically controllable mechanism. The fixing device 9 preferably includes a locking actuator 9a and a pin 9b, which, when actuated, protrudes from the frame 16 of the arm 6 toward the base 2 of the clamping system and enters an opening 5 in the base 2 and / or the frame of the AGV. The actuator 9a is preferably fixed at a first end to the upper frame element 16a and at a second end to the lower frame element 16b, and is preferably located between the lifting rods 18a, 18b. In a preferred embodiment, the actuator 9a is fixed to the lower frame element 16b via the pin 9b by inserting the pin 9b into an opening 3 in the lower frame element 16b. When the arm 6 is not locked by the locking device, the pin 9b remains inserted into the opening 3 in the retracted position. During locking of the arm 6, the actuator 9a causes the pin 9b to extend through the opening 3 and further into the opening 5 in the base 2 and / or the frame of the AGV. When locked, arm 6 is parallel to the centerline of the AGV body 4. During the unlocking of arm 6, actuator 9a causes pin 9b to retract from the opening 5 in the base 2 and / or the frame of the AGV.

[0022] The arm 6 may also include protective covers 30 on both sides of the arm 6.

[0023] The end effector 8 is connected to the sliding element 17 via a pivoting connector 10 to allow substantially free pivoting movement at the pivoting connector 10. The vertical position of the end effector 8 relative to the sliding element 17 is adjusted by sliding the sliding element 17 on the sliding rod 16c. The end effector 8 also includes a hook 11 for clamping a portion of the trolley frame and attaching it to one end of an elongated element 11.1. The elongated element 11.1 is linearly movable by an actuation device 12 (such as a linear actuator) such that a portion of the trolley frame is secured between the hook 11 and the front end face 21 of the end effector 8 when hooked. The actuation device 12 of the hook 11 preferably includes a drive member 12.1 and a guide member 12.2 for receiving, moving, and guiding the elongated element 11.1 for moving the hook 11. The guide member 12.2 is preferably disposed inside the bottom of the frame 15 of the end effector 8. A drive component 12.1 (such as a motor for driving the actuator) is preferably positioned near the sliding member 17 and upward relative to the guide member 12.2. The hook 11 also includes a sensor activation element 11a. Sensor activation element 11a activates a sensor 23, which is substantially positioned on the front end face 21 of the end actuator 8, generally opposite the hook 11. Sensor 11a is activated whenever the hook 11 is moved to the fully closed position by the hook actuator 12. This ensures that the AGV's control system receives information that the hook 11 has been moved to the fully closed position when no cart or other component is accidentally attached to the hook 11. Therefore, the AGV can safely switch to a cart-free operation mode. Two support brackets 13a, 13b are laterally positioned on the front end face 21 and on the right and left sides of the hook 11, respectively. Support brackets 13a, 13b, together with the hook 11, provide clamping force against the connecting parts of the cart. The end actuator 8 is also provided with side sensors 22a, 22b positioned within the frame 15 of the end actuator 8. Side sensors 22a and 22b are preferably pressure sensors. Each of the side sensors 22a and 22b is positioned between the center line of linear motion of the corresponding brackets 13a and 13b and the hook 11. Each of the side sensors 22a and 22b is activated by a corresponding sensor arm 20a and 20b, which is pivotally attached to the underside of the frame 15 of the end effector 8 and positioned between the center line of linear motion of the corresponding brackets 13a and 13b and the hook 11. The first ends 20a.1 and 20b.1 of each sensor arm 20a and 20b protrude from the front end face 21 of the end effector 8, such that when the end effector 8 begins to clamp the connecting part of the trolley, and when the end effector 8 is raised against the connecting part of the trolley, each sensor arm 20a and 20b is pressed downward by the connecting part of the trolley. The pivoting motion of each sensor arm 20a, 20b raises the second ends 20a.2, 20b.2 of the corresponding sensor arm 20a, 20b, thereby activating the corresponding pressure sensors 22a, 22b.When the end effector 8 is completely disengaged from the connecting parts of the trolley, the activation elements 11a, 20a, 20b of each of the end effector sensors 23, 22a, 22b disengage from the sensors 23, 22a, 22b, thus indicating that the end effector 8 is disengaged from the trolley frame.

[0024] During engagement of the end effector 8 with the trolley frame, the end effector 8 is raised against the trolley connection member. If the planes of the supports 13a, 13b are different from the plane of the trolley connection member, one of the two sensor arms 20a, 20b presses against the trolley connection member first. This causes the end effector 8 to pivot about its pivot point at the pivot connector 10, and thereby align with the plane of the trolley frame connection member until both sensor arms 20a, 20b are in contact with the trolley frame connection member and both side sensors 22a, 22b are finally activated. The two side sensors 22a, 22b are adapted to send signals to the AGV's control system, and the control unit is adapted to stop further raising of the end effector 8 when both side sensors 22a, 22b are activated.

[0025] When the end effector 8 and the connecting parts of the trolley frame are aligned, the control system sends a signal to the actuation device 12 of the hook 11 to move the hook 11 to the closed position, thereby pressing the connecting parts of the trolley against the brackets 13a and 13b.

[0026] When in operation with a trolley attached, the AGV and / or trolley can travel on uneven surfaces and roll relative to each other. If the connection between the trolley's frame and the clamping system is rigid in all directions, there is a risk of torsion between the hook / bracket and the trolley's connecting parts, and therefore a risk of losing the trolley and / or damaging the hook / bracket and / or trolley's connecting parts.

[0027] On the other hand, if the connection between the clamping system and the trolley frame is flexible in all directions (e.g., ball joint), the trolley's ability to steer precisely is lost.

[0028] With the end actuator 8 pivotally connected to the sliding element 17 at the pivot connector 10, the trolley and the AGV body 4 can roll partially relative to each other without twisting or squeezing the mechanical connection between them.

[0029] When the trolley is attached to the clamping system 1, arm 6 is preferably positioned at its center relative to the AGV. The AGV's control system identifies the trolley using a camera / sensor and has stored information about the height and position of the connected parts / frame of the identified trolley. The control system adjusts the height of the end effector 8 so that hook 11 is at a sufficiently low height to pass under the trolley frame / attachment. The AGV drives itself to a position in front of the trolley so that the end effector 8 is close to the frame / attachment. Hook 11 is driven outward. The end effector 8 is raised and hook 11 is driven inward until it, together with the supports 13a, 13b, provides clamping force on the trolley frame.

[0030] This structure ensures that essentially the same pulling force can be transmitted at different heights of the clamping section, thus enabling the pulling of different types of carts. Furthermore, the risk of the AGV tipping over is minimized.

[0031] Another aspect of the invention is to provide an AGV having the aforementioned clamping system 1. The AGV, which uses the clamping system 1 according to the first aspect of the invention to pull or push a wheeled cart, includes drive wheels, a robot body 4 mounted on the drive wheels, and a control system utilizing a navigation system. The AGV also includes proximity sensors 4.1 and 4.2 mounted on the robot body 4 for 270-degree observation around the robot body 4. One proximity sensor 4.1 is located in a rear corner of the robot body 4. The other proximity sensor 4.2 is located in a front corner of the robot body 4. The rear is the part to which the cart is attached, and the front is on the opposite side of the robot body 4. The control system is coupled to the proximity sensors 4.1 and 4.2 for adjusting the calculated robot position and for detecting any obstacles.

[0032] In a particularly preferred embodiment of the invention, the navigation system includes an automatic control and guidance system for reaching a given destination while avoiding collisions with the surrounding environment.

[0033] In the full text of this publication, AGV stands for Automated Guided Vehicle.

[0034] Although many features and advantages, as well as structural details and characteristics, have been set forth in this specification of the invention, the specification is provided with reference to exemplary implementations of the invention. Details, particularly form, size, and layout, may be varied without departing from the principles of the invention and with reference to the widest understanding of the concepts and definitions used in the claims.

Claims

1. A clamping system (1) for an automated guided vehicle (AGV), wherein the clamping system (1) comprises a base (2) for attaching the clamping system (1) to the AGV, an arm (6) for manipulating an end effector (8), and an end effector (8) for clamping a cart towed or pushed by the AGV, wherein the arm (6) is pivotally attached to the base (2) at one end for deflection movement of the arm (6) relative to the AGV, and an end effector (8) is provided at the other end for attachment to the arm (6), and comprises an arm (6) actuator (14) adapted to adjust the height of the end effector (8), characterized in that The end effector (8) is attached to the arm (6) via a pivoting connector (10) to allow rolling motion of the end effector (8) relative to the arm (6) while limiting deflection motion of the end effector relative to the arm. The end effector (8) includes two sensor arms (20a, 20b) which are adapted to pivot the end effector (8) about its pivoting connector (10) if only one of the sensor arms (20a, 20b) is pressed against the connecting member of the trolley frame, and wherein the sensor arms (20a, 20b) are arranged to activate side sensors (22a, 22b) for indicating that the end effector (8) is in the correct position to apply a clamping force to the connecting member of the trolley frame.

2. The clamping system according to claim 1, characterized in that, Each sensor arm (20a, 20b) for activating the side sensors (22a, 22b) has a first end (20a.1, 20b.1) protruding from the front end face (21) of the end actuator (8) for interacting with the frame of the trolley and a second end (20a.2, 20b.2) for interacting with the corresponding side sensor (22a, 22b).

3. The clamping system according to claim 2, characterized in that, The end effector (8) includes a hook (11) and a plurality of supports (13a, 13b) adapted to move the hook (11) in the direction of the front end face (21) of the end effector (8) by means of a hook actuation device (12) and apply a clamping force to the connecting member of the frame of the trolley.

4. The clamping system according to claim 3, characterized in that, The arm (6) includes a fixing device (9) for limiting the lateral movement of the arm (6), and the base (2) includes a portion (5) for interacting with the fixing device (9) to fix the arm (6) relative to the base (2).

5. The clamping system according to claim 4, characterized in that, The portion (5) for interacting with the fixing device (9) to fix the arm (6) relative to the base (2) is a groove or opening, and the fixing device (9) includes a locking actuator (9a) and a pin (9b) for interacting with the groove or opening (5).

6. The clamping system according to claim 5, characterized in that, The arm (6) includes a rigid frame (16) comprising an upper frame element (16a), a lower frame element (16b), and a sliding rod (16c). The sliding rod connects the upper frame element (16a) and the lower frame element (16b) and is a guide element for height adjustment of the end effector (8) by the sliding element (17), which is attached to the sliding element.

7. The clamping system according to claim 6, characterized in that, The arm (6) further includes a set of lifting rods (18a, 18b) and support rods (19a, 19b), wherein the lifting rods (18a, 18b) are pivotally attached at one end to the first end of the corresponding support rod (19a, 19b), and each support rod (19a, 19b) is pivotally attached at the second end of the support rod to the lower frame element (16b), and the lifting rods (18a, 18b) are pivotally attached at their second ends to the sliding element (17).

8. The clamping system according to claim 6, characterized in that, The actuator (14) of the arm (6) is fixed at one end to the lower frame element (16b) and at the other end to a set of lifting rods (18a, 18b).

9. The clamping system according to claim 3, characterized in that, The end effector (8) includes a sensor (23) and an activation element (11a) of the sensor (23), the activation element being attached to the hook (11) for activating the sensor (23) on the front end face (21) of the frame (15) attached to the end effector (8).

10. An automated guided vehicle, the automated guided vehicle comprising a clamping system (1) according to any one of claims 1-9.

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